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FT Cub Owners/builders thread- off topic allowed!

BATTLEAXE

Well-known member
#64
You can put them on any surface where you don't want airflow separation to occur at high AoA.

The pictures you took of the Kfox look really good, you just need bigger wheels, gosh I sound like someone from alabama trying to convince someone to put giant wheels on a truck:ROFLMAO:
I know it needs bigger wheels. I was looking at the FT store and saw some wheels at 4.3" foam tire style,
Link: https://store.flitetest.com/flite-test-4.3-foam-wheels-2-flt-2057/p676088
So @BATTLEAXE did the Whacker kinda hook you on bush planes?🤣
I was always hooked but it did have a place in the limited collection as a bush plane. It should be nice for take off and landing, slow and low, keeping it easy to fly. Just fits a niche
 

BATTLEAXE

Well-known member
#67
Got some work done on the wing today. It was time to install the ailerons. As you seen before I cut the aileron surfaces right off the wing because I wanted to step them down from the bottom of the wing. I already understand how the original ailerons work because every other FT plane uses the same paper/HG hinge and I seen this on the Kitfox which makes it unique, adds character and makes it recognizable.
20191225_153155.jpg

Here you can see the basic idea of the hinges, really simple. Had some laminated poster board left over from the wing fences. Did the tedious job of measuring, cutting, sanding, drilling, and assembly of these. I cut each side of the hinge the same as your average control horn and shaped the hinge corner round and both halves are hinged on bent up paper clips. The aileron is 20" wide, at 1" in from the end on either side leaves 18", divide the space up to 4 hinges evenly, you get 6" intervals.
20191225_153447.jpg

Looks pretty cool on the fuse...
20191225_153522.jpg

What it looks like from the top is the really unique part...
20191225_153701.jpg

Not only do they look cool but they have functionality. There is still the low speed kind of deflection that can be achieved. I have also found out that there might be a way to get the flapperons option on my Tx so I will be shooting for that one.

I have yet to fab up some VG's for it, which looking at how these hinges turned out, I might make them out of laminated poster board as well. I also am still waiting for servos to come in the mail and I need 2 more to get the ailerons working. I did get the tail wheel on and got the belly covered in the same color as the nose. The LG the way I have it set up for suspension with the rubber bands in the front, I did with the wire for the tail wheel, plane is all bouncy soft now. I might have to use a stronger rubber band for the main gear once I get all the weight into it with electronics and battery. And as it sits with just the motor on the firewall and battery in the center of the pod minus the ESC and Rx, it comes out nose heavy. Which is good because as I start adding more to it I can afford some weight to the tail. I dig it so far, looking promising
 

BATTLEAXE

Well-known member
#69
Thanks man it was pretty rewarding to see the final product. There are always uncertainties and unforeseeable's that show up with something new. This came together well. We will see how it holds up but it is a start.

Merry Christmas Bro
 
#76
I have been thinking about designing the KitFox for some time, for the same reasons as you. I really appreciate you sharing your thoughts. Do you foresee publishing drawings at some point?

I went off on the Schrubby tangent too. I like the way you guys think.
 

BATTLEAXE

Well-known member
#77
I have been thinking about designing the KitFox for some time, for the same reasons as you. I really appreciate you sharing your thoughts. Do you foresee publishing drawings at some point?

I went off on the Schrubby tangent too. I like the way you guys think.
I have never designed a plane to the point where it got to plans. For the most part I just modify existing plans till I get what I am looking for. Even this one I would make some changes to the fuse to make it more Kitfox instead of the shadow of one as far as aesthetics go. For the majority I just want to see how this wing flies.

Plus I would want to fly this a few times before I put out plans just to work out any detrimental issues if any that is. But if you wanted to try one we could collaborate on a build for you, it's really decently easy to do. It's just upscaled FT Cub plans and 3 view pic of the Kitfox tacked on the wall over the bench. "How do I make this, look like that" kinda deal :D

Have you modified FT planes before?
 

L Edge

Well-known member
#78
Just a little caution is required with the dimensions of VGs. As the Vortex is generated and centred around the upper edge of the VG it is possible if they are too tall that the generated vortex can actually cause lift to be lost at high angles of attack, at landing speeds. Instead of controlling the boundary flow if they are too tall they can actually destroy it.

In addition you need to consider the angle of incidence of the VG elements as they should be no more that 15 degrees with respect to the airflow and with an equal distribution of those pointing to the right and left. On swept wings remember that the VG elements should be angled with respect to the airflow and not angled with respect to the wing LE.

Have fun!
And the only way to show improvements is to put tufts on the wings and view it.
 
#79
I have never designed a plane to the point where it got to plans. For the most part I just modify existing plans till I get what I am looking for. Even this one I would make some changes to the fuse to make it more Kitfox instead of the shadow of one as far as aesthetics go. For the majority I just want to see how this wing flies.

Plus I would want to fly this a few times before I put out plans just to work out any detrimental issues if any that is. But if you wanted to try one we could collaborate on a build for you, it's really decently easy to do. It's just upscaled FT Cub plans and 3 view pic of the Kitfox tacked on the wall over the bench. "How do I make this, look like that" kinda deal :D

Have you modified FT planes before?
I have done a 120% GP and a 186% Simple Cub. Both added wood center spar, other minor tweaks.

The 120% GP also had a modified wing, taller spar to thicken wing... for huge increase in lift (and drag). Carried 3lbs cargo no problem. I think it could do at least 4lbs, maybe 5lbs which was my goal. With 3lbs in I was doing stall testing, and I didn't calculate my 2 mistakes high correctly or possibly the cargo shifted... regardless it was a spectacular test.

I love this design, and it's still my favorite after 10+ planes from FT.

My 186% Cub was to test what I hear Bix saying in the videos about "just 186% enlarge and go for it". generally speaking this hold true but you have to compensate for foam thickness in the A/B folds. But let me tell you it flies like a dream with 2x 4s1800 in the belly and Legacy landing gear/wheels. I did double thickness tail feathers too.

I am running Propdrive v2 3536 1400kv with 2x 4s1800 (or 2x3s2200) in the cub.

The only conclusion I have that was negative in the Cub is that the fuse is so wide it gets in the way of airflow off the prop. If I do this again I would want to thin the fuse some but that would take drawing mods.


I really love planes in the 1500-2000mm wingspan. Reality (and my car and not having to disassemble in order to transport) dictates 1200-1500mm is ideal.


Two designs on my mind these days, a KitFox and something (anything) modded to 100+ mph. I think the KitFox should take my 3536 drivetrain or the Emax GT2815 I have on order. these two motors have about the same thrust ratings from what I have read. I am still trying to understand how these very different sizes can output the same thrust. Yes, motor weight is about the same, giving credence to the thrust per gram concept.
 

BATTLEAXE

Well-known member
#80
I think the KitFox should take my 3536 drivetrain
That's the same size of motor I am using in mine, 11x7x3 M.A. prop. It should create plenty of lift just off the propwash alone. And really for the size of this Kitfoxxy thing I am doing it is actually surprisingly light to hold compared to what would be expected. Mind you once all the electronics have been fitted in that's when things start getting real.

I do have room in the power pod for a 5450mah 120C 3s for extended flights, I have a new cam coming in the mail so there might be some pilot view on board footage going on. I would also like to program flapperons into it as well.